The purpose of the research is to determine whether dextroamphetamine--a stimulant drug treatment--has a beneficial effect on the language performance and communicative skills of different groups of normal and learning disabled boys: hyperactive boys with impaired language development, hyperactive boys with normal language development and impaired communicative skills and normal boys with superior language and communicative skills. Dextroamphetamine was found to have a beneficial effect on the language and Communicative skills of all three groups studied, although the effects differed in each group. The group most benefited by drug administration were the normal subjects whose task directed communicative speech increased in fluency and complexity. Both hyperactive groups were benefited. Those impaired in language development increased most in their linguistic complexity and language task performance while those only impaired in communication were only aided by a decrease in their non-task directed speech. Their task directed communicative speech fluency was not increased as in the normal subjects.